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Checking & Adjusting your Nutrients & pH (Part 3 of 4)

Part 3 of 4: How to check and adjust the nutrient and pH levels in your Flex Acre

After Cleaning your Disc Filter (Part 2 of 4), water is moving cleanly and you can check your levels. Check your nutrients and your pH in the same visit, twice a week. Add your nutrients first, then pH Down if it is needed. Follow the steps in Keeping your Flex Acre Clean before you begin.

Your Flex Acre works exactly the way a Flex Farm does, with about four times the water, so every measurement below is scaled to your 80 gallon Tank.

Gather Tools:

Step 1: Top Off your Water

  1. Check the level in your Tank against the Water Level Tool.
  2. Top off with fresh water until the level reaches the MAX line, roughly 80 gallons.

Top off before you read anything. Water added afterwards dilutes what you just dosed and both readings drift. Most Flex Acres take 20 to 30 gallons a week.

Step 2: Check your Nutrient Level

  1. Turn on your TDS Meter. It should read 0 PPM.
  2. Fill your measuring cup with water from your Tank.
  3. Dip the lower part of the meter 1 to 2 inches into the cup.
  4. Wait 5 to 10 seconds, then press and hold the HOLD button.
  5. Read the number on the screen.

NOTE: YOUR TDS METER IS NOT WATERPROOF. DO NOT SUBMERGE IT MORE THAN 1 TO 2 INCHES.

Your Target Number is the reading of your plain water plus 700. Take that plain water reading once, when your Tank is fresh, and it stays your Base Number until your next water refresh. Both numbers have a space on your Flex Acre Quick Reference Guide.

Step 3: Add your Nutrients

  1. Fill your bucket with 4 cups of water and stir in 4 tablespoons of Nutrient A until it dissolves.
  2. Pour it into the pump side of your Tank.
  3. Rinse the bucket, then repeat with 4 tablespoons of Nutrient B in 4 cups of water.
  4. Stir your Tank with your stirring paddle.

CAUTION: NEVER MIX NUTRIENT A AND NUTRIENT B TOGETHER IN THE SAME BUCKET. DISSOLVE AND POUR ONE AT A TIME.

Always add equal amounts of Nutrient A and Nutrient B. Four tablespoons of each raises your Flex Acre by roughly 230 PPM. Dissolving them in water first matters most for Nutrient B, which will not break down if it goes straight into the Tank. Use the nutrients and pH Down supplied by Fork Farms. They are matched to your Flex Acre.

  • Within 100 PPM of your Target Number. You are in range. Nothing more is needed.
  • More than 100 PPM below. Add another 4 tablespoons of each, dissolved separately.
  • More than 100 PPM above. Remove some water and top back up with fresh water.

Step 4: Check your pH

  1. Fill the vial from your pH Test Kit with 5 ml of water from your Tank, about halfway.
  2. Add 5 drops of the test solution.
  3. Shake to mix.
  4. Compare the color against the chart on the bottle.

Your target pH is 5.5 to 6.0. There is no need to adjust while you are within 0.5 of that.

Step 5: Adjust your pH

  1. Add 4 tablespoons of pH Down when your reading sits above the target.
  2. Stir your Tank with your stirring paddle.
  3. Remove some water and top back up with fresh water when your reading sits below the target.

Four tablespoons of pH Down moves a full Tank by roughly 1.0, and a brand new Tank of fresh water can take 8 tablespoons or more before it settles. Fork Farms supplies pH Down only, so a low reading is corrected with fresh water rather than a second bottle.

Step 6: Check Again in a Few Days

  1. Record your nutrient reading, your pH and the date in your Data Log.
  2. Check both again on your next visit, a few days later.
  3. Adjust again from there if either has drifted.

You do not need to stand and wait. Your pump keeps cycling, the Tank evens out on its own, and both numbers settle over the next couple of days. Adjusting in small amounts twice a week is what keeps your Flex Acre steady, and it is far easier than trying to land both numbers in one visit. Record what you added as described in Logging your Flex Acre Tasks & Readings.

NOTE: IF YOU ARE TRANSPLANTING, YOUR NUTRIENT AND PH LEVELS DO NOT NEED TO BE IN RANGE BEFORE YOU BEGIN. ADJUST AND TRANSPLANT ON THE SAME DAY, THEN KEEP CHECKING OVER THE NEXT FEW DAYS.

If your readings land on target but your plants still show yellowing leaves, stunted growth or purple discoloration, check your pH first, as a pH out of range is the most common reason nutrients stop being available to the crop. If your pH is in range and the signs continue, contact our support team.

Your Tank is fed and balanced—well done!

Next: Wiping Light Bars & Pruning your Plants (Part 4 of 4)